Depth Perception
Depth Cues
The way in which humans see, perceive, and interpret depth cues is a well-studied problem about which much has been written. (See the references for several starting points into this vast literature.) Our focus in this section is on stereopsis, but it is useful as a prelude to understand its relationship to and interaction with other depth perception cues. Hence we shall begin by studying depth perception in general.
Cues that allow us to perceive depth – and in particular, to perceive relative depth relationships among a set of objects in our field of view – are frequently divided into two categories:
- monocular cues (those that can be perceived using a single eye)
- binocular cues (those that require a merging of sensory input from both eyes)
While not all authors agree on the specific way in which the various cues are placed with respect to these (or even other) categories, they all describe essentially the same set of cues. Here we will present them using what appears to be the most frequently used categorization and description.
Stereopsis is a binocular cue. In particular, it is the exploitation of retinal disparity (the second of the binocular cues we will study) that enables stereoscopic display technology.
